title: An analytical Raman spectroscopic study of an important english oil painting of the 18th Century.
abstract: An opportunity was afforded to analyse pigment specimens from an unrestored oil painting in the style of the English School of the mid-18th Century prior to conservation being undertaken. Raman spectroscopy was adopted to characterise the pigments and indicated the presence of a novel red pigment which was assigned to the complex chromium mineral, hemihedrite, in addition to other interesting materials found in combination. This is the first recorded identification of hemihedrite spectral signals in an art context in a range of mineral pigments that are otherwise typical of this period and some hypotheses are presented to explain its presence based on its occurrence with associated mineral pigments. It is suggested that the presence of powdered glass identified in certain areas of the painting enhanced the reflectivity of the pigment matrix.
authors.affiliation: Chemical and Forensic Sciences, School of Life Sciences, University of Bradford, Bradford BD7 1DP, UK. Electronic address: h.g.m.edwards@bradford.ac.uk.
authors.forename: Howell G M
authors.initials: HG
authors.lastname: Edwards
authors.forename: Peter
authors.initials: P
authors.lastname: Vandenabeele
authors.forename: Jan
authors.initials: J
authors.lastname: Jehlicka
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Benoy
mesh_terms: D002857:Chromium / Q000032:analysis / Q000266:history; D004396:Coloring Agents / Q000032:analysis* / Q000266:history; D004739:England; D049671:History, 18th Century; D008903:Minerals / Q000032:analysis / Q000266:history; D010150:Paint / Q000032:analysis* / Q000266:history*; D010151:Paintings / Q000266:history*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D004396:Coloring Agents; D008903:Minerals; D002857:Chromium
keywords: Gainsborough; Hemihedrite; Mineral pigments; Oil painting; Raman spectroscopy